Provocative mesenteric angiography for localizing ambiguous gastrointestinal hemorrhage

Abstract
Objectives: Five percent of patients with recurrent gastrointestinal (GI) hemorrhage have indeterminate origin by radiological and endoscopic examinations. To improve diagnostic accuracy and therapeutic embolization, the technique of provocative mesenteric angiography (PMA) has been developed. It involves the addition of pharmacologic agents to standard angiographic protocols to induce bleeding. Material and Methods: This is an institutional review board-approved, retrospective study of 20 patients who underwent PMA between 2014 and 2019. All patients had clinical evidence of GI hemorrhage without a definite source. PMA consisted of anticoagulation with 5000 units of heparin and selective transcatheter injection of up to 600 μg of nitroglycerine, followed by slow infusion of up to 24 mg of tissue plasminogen activator into the arterial distribution of the highest suspicion mesenteric artery. Results: Among the 20 patients who underwent PMA, 11/20 (55%) resulted in angiographically visible extravasation. Of these 11 patients, nine patients underwent successful embolization with coil or glue and were discharged upon achieving hemodynamic stability. Two patients spontaneously stopped bleeding. In our series, PMA resulted in the successful treatment of 9/20 (45%) patients with recurrent hemorrhage. No procedure-associated complications were reported with these 20 patients during the procedure and their course of hospitalization. Conclusion: In our experience, PMA is an effective and safe approach in localizing and treating the source of GI bleeding in about half of patients with an otherwise unidentifiable source.